This disclosure relates generally to a battery pack and, more particularly, to a separator between battery cells of the pack. This separator provides a dielectric and a path for venting the battery cells.
Generally, electric vehicles differ from conventional motor vehicles because electric vehicles are selectively driven using one or more battery-powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on an internal combustion engine to drive the vehicle. Electric vehicles may use electric machines instead of, or in addition to, the internal combustion engine.
Example electric vehicles include hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles, and battery electric vehicles (BEVs). A powertrain of an electric vehicle is typically equipped with a battery pack having battery cells that store electrical power for powering the electric machine. The battery cells may be charged prior to use. The battery cells may be recharged during a drive by regeneration braking or an internal combustion engine.
From time to time, fluid within the interiors of some types of battery cells, such as lithium ion battery cells, can undesirably expand. Confining the expanding fluid within the interiors of the battery cells can cause the battery cells to swell undesirably. Each battery cell is thus typically equipped with a vent.
In some examples, the vent is closed during operation. If fluid within the interior of the battery cell expands, the expanding fluid opens the vent. The open path provides a path for the expanding fluid to escape from the interior. The venting prevents the expanding fluid from swelling the battery cell.
Removing the vented fluid from the vehicle is often required so that, for example, the vented fluid does not enter a cabin of the vehicle. Providing a vent path to communicate and contain the vented fluid can require many components and complicated assembly steps.